This undated photo provided by Paul Hanson shows his sister, Dianna Hanson. Dianna Hanson, a 24-year-old intern at the Cat Haven in Dunlap, Calif., was mauled to death by a lion at the exotic animal park on Wednesday, March 6, 2013.

"Even though she was only with us for a little over two months, she was part of our family," said Wendy Debbas, the president of Project Survival Cat Haven, a non-profit group associated with the sanctuary. "She made instant friendships with everybody up here. Everybody loved her.

"She has songs she made up for each of the cats," Debbas told reporters this evening. "A cute example of that is we have jaguar cubs named Samba and Rose. Samba's song was not 'La Bamba' but 'La Samba.' And Rose was 'Kissed by a Rose.' And she had songs like that for all of the cats. She was vivacious. She loved her work. She loved big cats."

Hanson's father said today that she never feared working with big cats, but he always feared something might happen to her.

"Anybody who works with cats knows that they are wild animals and they can turn even on people closest to them. So I always had this horrible, nagging premonition that I would get a call like this," Hanson's father, Paul, told ABC News overnight by phone from his home in Washington state.

Hanson said his daughter loved to be around big cats and that working with them was her true passion in life.

Dianna Hanson was inside the cat enclosure when a Cous Cous attacked her around 12:30 p.m., officials said. It was not immediately clear what Hanson was doing inside the enclosure or what prompted the attack.

Another employee tried unsuccessfully to lure Cous Cous away from Hanson and into another enclosure.

Less than 30 minutes after Hanson entered the cage, Cous Cous was shot by a Fresno County sheriff's deputy who responded to a call, authorities said.

Hanson's grief-stricken father is now left with the question of why his daughter was in the enclosure with the lion.

"How she ever got inside the cage and why she would be inside the cage [is unclear], because I thought she made it real clear that they don't let anybody in the cage except the owner," Paul Hanson said.

In a statement on Facebook, Hanson reflected on his daughter's time working at the sanctuary.

"Once there, she gave me the tour and showed me all the big cats there with which she would be working. Of course, Dianna being Dianna, her favorites were the tiger and the lion ... who killed her today," he said.

Dianna Hanson trained with three tigers and a lion while in college at Western Washington State University. She also traveled to Africa to work with large cats, Paul Hanson said.